1. Field of the Invention
This invention relates in general to devices which can recover and recycle, or recover, recycle and recharge refrigerants, and more particularly to a device which can recover, recycle and recharge refrigerants such as R-12 from air conditioning systems used in automobiles, trucks and similar vehicles.
2. Prior Art
With the recognition of the importance of the ozone layer in the Earth's atmosphere, and that chlorofluorocarbons (CFC) which were being emitted into the atmosphere were primarily responsible for the depletion of the ozone layer, concerted efforts have been and are being made to reduce the amount of CFC being emitted into the atmosphere.
One major source of CFC being emitted into the atmosphere is the refrigerant R-12 used in air conditioning systems found in automobiles, trucks and other vehicles. As a result of the recognition of this particular problem various standards have been set by both Underwriters Laboratories (UL) and the Society of Automotive Engineers (SAE) for the procedure and equipment characteristics to be used in the recovery and purification of R-12 in refrigerant systems, rather than to simply vent the used refrigerant to the atmosphere. To comply with these standards industry has designed and currently markets a multitude of recovery and recycling systems for R-12.
As used herein the term "recycled refrigerant" shall mean used refrigerant that has been cleaned of oil, moisture, solids and non-condensible gases to the extent necessary to meet the current UL published safety standards set forth in UL 1963 entitled "Standard for Safety Refrigerant Recovery/Recycling Equipment" and the current SAE published standards set forth in J1989 entitled "Service Procedure for Containment of R-12", J1990 entitled "Extraction and Recycle Equipment for Mobile Automotive Air Conditioning Systems" and J1991 entitled "Reclamation of R-12 Used in Mobile Air Conditioning Systems for Cleanliness".
The following are illustrative of commercial systems which process used refrigerant to produce recycled refrigerant: Wynn's Climate Systems, Inc.'s Refrigerant Recovery/Recycle System Model 9001A; SPX Robinair Division's Refrigerant Recovery and Recycling Station Models 17200, 17400, and 17500; Van Steenburgh Engineering Laboratories, Inc.'s Refrigerant Reclaim System Models Series LV and Series JV; K-Whit Tools, Inc's White Industries Division Refrigerant Recovery Recycling Center Models 01050 and 04000; Standard Motor Products, Inc.'s Four Seasons Division Refrigerant Recovery and Recycling Center Model 59870; and Refrigerant Technologies, Inc. Model RRC 1000.
In addition to the commercial products the following U.S. patents are also illustrative of the state of the art in refrigerant recovery and recycling of R-12 and other similar refrigerants: 3212284; 3232070; 4261178; 4285206; 4363222; 4476688; 4539817; 4646527; 4768347; 4805416; 4809520; 4878356; and 4903499.
Although these prior art devices can recover and recycle R-12 and other similar refrigerants, and some recover, recycle and recharge R-12, their design does not allow for the control desired when in use under actual commercial conditions. Many of these devices do not allow for easy and accurate determination that sufficient amounts of non-condensible material present in the used refrigerant have been removed. Others do not allow for the purging of air vapor that may be in the recycled refrigerant prior to being recharged to the automobile, truck or other vehicle air conditioning system. Still others are too temperature sensitive in the transferability of the refrigerant within the device. Others have no control of the level of refrigerant in the collection tank. Further problems with many of the prior art devices is control of the different procedures that can take place during the recover Another problem is the ability to accurately recharge the correct amount of recycled refrigerant back to the air conditioning system.